New Delhi: The discovery of ripples in spacetime—gravitational waves—which shook the scientific world this year, has now been declared as the...

New Delhi: The discovery of ripples in spacetime—gravitational waves—which shook the scientific world this year, has now been declared as the scientific breakthrough of 2016 by the prestigious magazine Science.The discovery fulfilled a prediction made 100 years ago by Albert Einstein and capped a 40-year quest to spot the infinitesimal ripples, according to Adrian Cho, a staff writer with Science.

In 1915, Einstein explained that gravity arises because massive bodies warp space and time, or spacetime, causing free-falling objects to follow curved paths such as the arc of a thrown ball or the elliptical orbit of a planet around its sun.Einstein then calculated that a barbell-shaped distribution of mass whirling end-to-end like a baton should radiate ripples in spacetime that zip along at speed of light – which he described as ‘gravitational waves’.

On 11 February, physicists working with the Laser Interferometer Gravitational-Wave Observatory (LIGO)—twin instruments in Hanford, Washington, and Livingston, Louisiana—announced that they had seen just what Einstein predicted: a burst of waves created as two black holes spiraled into each other 1 point 3 billion light-years away.

The other runner ups in the scientific breakthroughs of the year included the discovery of a small planet around Earth’s very closest star, Proxima Centauri.Astronomers hailed the new world as our best opportunity to study in detail a planet outside our solar system, and are already straining to find out what it is like, writes Daniel Clery of Science.Tiny shifts in the frequency of Proxima Centauri’s light revealed the planet, dubbed Proxima b.

This year, artificial intelligence (AI) passed a significant milestone when a computer program called AlphaGo beat the world’s No 2 Go player in a five-game match.It’s not the first time that AI has surpassed human mastery of a game.After all, it was 20 years ago that IBM’s Deep Blue first beat Garry Kasparov in a game of chess, toppling the world champion the following year in a six-game match.

But that is where the similarity ends.The rules of Go are more straightforward than those of chess: You simply place identical stones on a grid, capturing territory by surrounding your opponent’s positions.But that simplicity and openness result in an explosion in the number of possible moves for a player to consider—far more than there are atoms in the known universe.

That makes it impossible for AI to beat Go masters with an approach like that used by Deep Blue, which relies on hand-coded strategies from chess experts to evaluate each possible move, writes Science writer John Bohannon.Killing old cells to stay young is another breakthrough, scientists have discovered.Pricey plastic surgery won’t stop you from getting old; nor will dietary supplements, testosterone injections, or those wrinkle creams that imply they’ll make you look 21 again.

But this year, researchers demonstrated one way to postpone some ravages of time—at least in mice.When they selectively weeded out run-down cells, the animals lived longer and remained healthier as they aged.Another breakthrough of 2016 was that Great apes demonstrated a mind-reading skill that only humans were thought to fully possess.

Known as theory of mind, it is the ability to discern desires, intentions, and knowledge in others.Some tests had shown that our close relatives have enough insight to, for example, deceive a fellow ape or recognize another’s motives.But until now, they had always failed in tasks that require the ability to determine when others hold a false belief.Proteins are life’s workhorses, writes Robert F Service, a news report for Science.

Given proteins’ talents, researchers have long wanted to create their own versions.They have modified many existing proteins by making small tweaks to an organism’s DNA code, but this year, they took protein modification to a whole new level: They created a suite of designer proteins unlike anything found in nature, setting the stage for novel medicines and materials.

Another interesting achievement gave new meaning to the term “test-tube babies,” this year, when researchers in Japan produced mouse pups from egg cells grown entirely in a lab dish.This long-sought achievement offers researchers a new way to study egg development and raises the more distant prospect of making human eggs in the lab from almost any type of cell, including genetically altered ones.

That possibility has sparked hope for new infertility treatments, but it has also revived fears about designer babies.Another story of our species is that they are driven by wanderlust.Born in Africa, our species Homo sapiens expanded into the far corners of the globe in the past 100,000 years, meeting and mingling with more archaic human-like hominins already living there, says Elizabeth Culotta, a deputy news editor at Science.

But researchers have long debated how and when modern humans left Africa: Was it in a single migration or in repeated waves? In 2016, a burst of genomic data all but clinched the case that most living people outside Africa descend from a single migration; any earlier migrations were mostly swamped by this last wave.In a trio of studies, Genome sequencing may be on the verge of becoming a ubiquitous tool in biology, both in the lab and—perhaps more important—in the field, thanks to a handheld device that became widely available for the first time this year.

It is already generating scores of research papers.Glass lenses were one of humanity’s earliest high-tech innovations.They enabled Galileo to see Jupiter’s moons, Antonie van Leeuwenhoek to spy microbes, and millions of people to just plain see clearly.

But lenses are still made roughly the same way as they were centuries ago—by grinding and polishing glass and other transparent materials so that they focus light without aberration.Now, lens technology is poised to take a major leap.This year, researchers used computer chip–patterning techniques to create the first metamaterial lens, or metalens, that can focus the full spectrum of visible light.Because metalenses are cheap to produce, thinner than a sheet of paper, and far lighter than glass, they could revolutionize everything from microscopes to virtual reality displays to cameras—including the ones in your smart phone, adds Robert Service.